Problem type checking ancestors() with pyright

[jlhamilton777]

Information

• rustworkx version: 0.15.1
• Python version: 3.12.4
• Rust version: 1.79.0
• Operating system: Void Linux x86_64

What is the current behavior?

Pyright is unable to fully type check the rustworkx.ancestors() function in strict mode.

What is the expected behavior?

Pyright should be able to determine the type of ancestors(), including the parameterized type of the graph parameter.

Steps to reproduce the problem

# pyright: strict

import rustworkx as rx

graph: rx.PyDiGraph[int, float] = rx.PyDiGraph()
node = graph.add_node(7)
rx.ancestors(graph, node)

$ pyright .
./main.py
  ./main.py:7:1 - error: Type of "ancestors" is partially unknown
    Type of "ancestors" is "(graph: PyDiGraph[Unknown, Unknown], node: int, /) -> set[int]" (reportUnknownMemberType)
1 error, 0 warnings, 0 informations

I looked at the stub file

rustworkx/rustworkx/rustworkx.pyi

Lines 985 to 990 in 553bff1

	def digraph_dfs_edges(graph: PyDiGraph[_S, _T], /, source: int | None = ...) -> EdgeList: ...
	def graph_dfs_edges(graph: PyGraph[_S, _T], /, source: int | None = ...) -> EdgeList: ...
	def ancestors(graph: PyDiGraph, node: int, /) -> set[int]: ...
	def bfs_predecessors(graph: PyDiGraph, node: int, /) -> BFSPredecessors: ...
	def bfs_successors(graph: PyDiGraph, node: int, /) -> BFSSuccessors: ...
	def descendants(graph: PyDiGraph, node: int, /) -> set[int]: ...

and graph doesn't have PyDiGraph[_S, _T] like in some of the other functions. I also ran into this issue with the descendants() function.

[IvanIsCoding]

We can replace the signature with PyDiGraph[Any,Any], but honestly that is a pyright quirk from microsoft/pyright#5101.

Mypy treat it as Any which is what we tested for. I’ll explore how Pyre and Pytype treat it so we can have a solution that works well with most type checkers

[max-muoto]

We can replace the signature with PyDiGraph[Any,Any], but honestly that is a pyright quirk from microsoft/pyright#5101.

Mypy treat it as Any which is what we tested for. I’ll explore how Pyre and Pytype treat it so we can have a solution that works well with most type checkers

What might work well across type checkers is relying on type vars defaults in the typing extensions backport of TypeVar. You can default the keys/values to Any.

[IvanIsCoding]

We can replace the signature with PyDiGraph[Any,Any], but honestly that is a pyright quirk from microsoft/pyright#5101.
Mypy treat it as Any which is what we tested for. I’ll explore how Pyre and Pytype treat it so we can have a solution that works well with most type checkers

What might work well across type checkers is relying on type vars defaults in the typing extensions backport of TypeVar. You can default the keys/values to Any.

I think that is the best solution, although I am not going to backport a fix depending on typing_extension. So maybe for 0.16.x.